Currently btrfs_validate_super() only does a very basic check on the
array chunk size (not too large than the available space, but not too
small to contain no chunk).
The more comprehensive checks (the regular chunk checks and size check
inside the system chunk array) are all done inside btrfs_read_sys_array().
It's not a big deal, but it also means we do not do any validation on
the system chunk array at super block writeback time either.
Do the following modification to centralize the system chunk array
checks into btrfs_validate_super():
- Make chunk_err() helper accept stack chunk pointer
If @leaf parameter is NULL, then the @chunk pointer will be a pointer
to the chunk item, other than the offset inside the leaf.
And since @leaf can be NULL, add a new @fs_info parameter for that
case.
- Make btrfs_check_chunk_valid() handle stack chunk pointer
The same as chunk_err(), a new @fs_info parameter, and if @leaf is
NULL, then @chunk will be a pointer to a stack chunk.
If @chunk is NULL, then all needed btrfs_chunk members will be read
using the stack helper instead of the leaf helper.
This means we need to read out all the needed member at the beginning
of the function.
Furthermore, at super block read time, fs_info->sectorsize is not yet
initialized, we need one extra @sectorsize parameter to grab the
correct sectorsize.
- Introduce a helper validate_sys_chunk_array()
* Validate the disk key.
* Validate the size before we access the full chunk items.
* Do the full chunk item validation.
- Call validate_sys_chunk_array() at btrfs_validate_super()
- Simplify the checks inside btrfs_read_sys_array()
Now the checks will be converted to an ASSERT().
- Simplify the checks inside read_one_chunk()
Now that all chunk items inside system chunk array and chunk tree are
verified, there is no need to verify them again inside read_one_chunk().
This change has the following advantages:
- More comprehensive checks at write time
And unlike the sys_chunk_array read routine, this time we do not need
to allocate a dummy extent buffer to do the check.
All the checks done here require no new memory allocation.
- Slightly improved readability when iterating the system chunk array
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The only caller of btrfs_verify_level_key() is read_block_for_search() and
it's passing 3 arguments to it that can be extracted from its on stack
variable of type struct btrfs_tree_parent_check.
So change btrfs_verify_level_key() to accept an argument of type
struct btrfs_tree_parent_check instead of level, first key and parent
transid arguments.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We previously would call btrfs_check_leaf() if we had the check
integrity code enabled, which meant that we could only run the extended
leaf checks if we had WRITTEN set on the header flags.
This leaves a gap in our checking, because we could end up with
corruption on disk where WRITTEN isn't set on the leaf, and then the
extended leaf checks don't get run which we rely on to validate all of
the item pointers to make sure we don't access memory outside of the
extent buffer.
However, since 732fab95ab ("btrfs: check-integrity: remove
CONFIG_BTRFS_FS_CHECK_INTEGRITY option") we no longer call
btrfs_check_leaf() from btrfs_mark_buffer_dirty(), which means we only
ever call it on blocks that are being written out, and thus have WRITTEN
set, or that are being read in, which should have WRITTEN set.
Add checks to make sure we have WRITTEN set appropriately, and then make
sure __btrfs_check_leaf() always does the item checking. This will
protect us from file systems that have been corrupted and no longer have
WRITTEN set on some of the blocks.
This was hit on a crafted image tweaking the WRITTEN bit and reported by
KASAN as out-of-bound access in the eb accessors. The example is a dir
item at the end of an eb.
[2.042] BTRFS warning (device loop1): bad eb member start: ptr 0x3fff start 30572544 member offset 16410 size 2
[2.040] general protection fault, probably for non-canonical address 0xe0009d1000000003: 0000 [#1] PREEMPT SMP KASAN NOPTI
[2.537] KASAN: maybe wild-memory-access in range [0x0005088000000018-0x000508800000001f]
[2.729] CPU: 0 PID: 2587 Comm: mount Not tainted 6.8.2 #1
[2.729] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
[2.621] RIP: 0010:btrfs_get_16+0x34b/0x6d0
[2.621] RSP: 0018:ffff88810871fab8 EFLAGS: 00000206
[2.621] RAX: 0000a11000000003 RBX: ffff888104ff8720 RCX: ffff88811b2288c0
[2.621] RDX: dffffc0000000000 RSI: ffffffff81dd8aca RDI: ffff88810871f748
[2.621] RBP: 000000000000401a R08: 0000000000000001 R09: ffffed10210e3ee9
[2.621] R10: ffff88810871f74f R11: 205d323430333737 R12: 000000000000001a
[2.621] R13: 000508800000001a R14: 1ffff110210e3f5d R15: ffffffff850011e8
[2.621] FS: 00007f56ea275840(0000) GS:ffff88811b200000(0000) knlGS:0000000000000000
[2.621] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[2.621] CR2: 00007febd13b75c0 CR3: 000000010bb50000 CR4: 00000000000006f0
[2.621] Call Trace:
[2.621] <TASK>
[2.621] ? show_regs+0x74/0x80
[2.621] ? die_addr+0x46/0xc0
[2.621] ? exc_general_protection+0x161/0x2a0
[2.621] ? asm_exc_general_protection+0x26/0x30
[2.621] ? btrfs_get_16+0x33a/0x6d0
[2.621] ? btrfs_get_16+0x34b/0x6d0
[2.621] ? btrfs_get_16+0x33a/0x6d0
[2.621] ? __pfx_btrfs_get_16+0x10/0x10
[2.621] ? __pfx_mutex_unlock+0x10/0x10
[2.621] btrfs_match_dir_item_name+0x101/0x1a0
[2.621] btrfs_lookup_dir_item+0x1f3/0x280
[2.621] ? __pfx_btrfs_lookup_dir_item+0x10/0x10
[2.621] btrfs_get_tree+0xd25/0x1910
Reported-by: lei lu <llfamsec@gmail.com>
CC: stable@vger.kernel.org # 6.7+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ copy more details from report ]
Signed-off-by: David Sterba <dsterba@suse.com>
Do a cleanup in more headers:
- add forward declarations for types referenced by pointers
- add includes when types need them
This fixes potential compilation problems if the headers are reordered
or the missing includes are not provided indirectly.
Signed-off-by: David Sterba <dsterba@suse.com>
This is more a buffer validation helper, move it into the tree-checker
files where it makes more sense.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This helper returns a btrfs_tree_block_status for the various errors,
and then btrfs_check_node() will return -EUCLEAN if it gets anything
other than BTRFS_TREE_BLOCK_CLEAN which will be used by the kernel. In
the future btrfs-progs will use this helper instead.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Instead of blanket returning -EUCLEAN for all the failures in
btrfs_check_leaf, use btrfs_tree_block_status and return the appropriate
status for each failure. Rename the helper to __btrfs_check_leaf and
then make a wrapper of btrfs_check_leaf that will return -EUCLEAN to
non-clean error codes. This will allow us to have the
__btrfs_check_leaf variant in btrfs-progs while keeping the behavior in
the kernel consistent.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We use this in btrfs-progs to determine if we can fix different types of
corruptions. We don't care about this in the kernel, however it would
be good to share this code between the kernel and btrfs-progs, so add
the status definitions so we can start converting the tree-checker code
over to using these status flags instead of blanket returning -EUCLEAN.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We have two helpers for checking leaves, because we have an extra check
for debugging in btrfs_mark_buffer_dirty(), and at that stage we may
have item data that isn't consistent yet. However we can handle this
case internally in the helper, if BTRFS_HEADER_FLAG_WRITTEN is set we
know the buffer should be internally consistent, otherwise we need to
skip checking the item data.
Simplify this helper down a single helper and handle the item data
checking logic internally to the helper.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Move struct btrfs_tree_parent_check out of disk-io.h so that volumes.h
an various .c files don't have to include disk-io.h just for it.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
[ use tree-checker.h for the structure ]
Signed-off-by: David Sterba <dsterba@suse.com>
Btrfs doesn't check whether the tree block respects the root owner.
This means, if a tree block referred by a parent in extent tree, but has
owner of 5, btrfs can still continue reading the tree block, as long as
it doesn't trigger other sanity checks.
Normally this is fine, but combined with the empty tree check in
check_leaf(), if we hit an empty extent tree, but the root node has
csum tree owner, we can let such extent buffer to sneak in.
Shrink the hole by:
- Do extra eb owner check at tree read time
- Make sure the root owner extent buffer exactly matches the root id.
Unfortunately we can't yet completely patch the hole, there are several
call sites can't pass all info we need:
- For reloc/log trees
Their owner is key::offset, not key::objectid.
We need the full root key to do that accurate check.
For now, we just skip the ownership check for those trees.
- For add_data_references() of relocation
That call site doesn't have any parent/ownership info, as all the
bytenrs are all from btrfs_find_all_leafs().
- For direct backref items walk
Direct backref items records the parent bytenr directly, thus unlike
indirect backref item, we don't do a full tree search.
Thus in that case, we don't have full parent owner to check.
For the later two cases, they all pass 0 as @owner_root, thus we can
skip those cases if @owner_root is 0.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
By function, chunk item verification is more suitable to be done inside
tree-checker.
So move btrfs_check_chunk_valid() to tree-checker.c and export it.
And since it's now moved to tree-checker, also add a better comment for
what this function is doing.
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Remove GPL boilerplate text (long, short, one-line) and keep the rest,
ie. personal, company or original source copyright statements. Add the
SPDX header.
Unify the include protection macros to match the file names.
Signed-off-by: David Sterba <dsterba@suse.com>
When inspecting the error message with real corruption, the "root=%llu"
always shows "1" (root tree), instead of the correct owner.
The problem is that we are getting @root from page->mapping->host, which
points the same btree inode, so we will always get the same root.
This makes the root owner output meaningless, and harder to port
tree-checker to btrfs-progs.
So get rid of the false and meaningless @root parameter and replace it
with @fs_info.
To get the owner, we can only rely on btrfs_header_owner() now.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
If we run btrfs with CONFIG_BTRFS_FS_RUN_SANITY_TESTS=y, it will
instantly cause kernel panic like:
------
...
assertion failed: 0, file: fs/btrfs/disk-io.c, line: 3853
...
Call Trace:
btrfs_mark_buffer_dirty+0x187/0x1f0 [btrfs]
setup_items_for_insert+0x385/0x650 [btrfs]
__btrfs_drop_extents+0x129a/0x1870 [btrfs]
...
-----
[Cause]
Btrfs will call btrfs_check_leaf() in btrfs_mark_buffer_dirty() to check
if the leaf is valid with CONFIG_BTRFS_FS_RUN_SANITY_TESTS=y.
However quite some btrfs_mark_buffer_dirty() callers(*) don't really
initialize its item data but only initialize its item pointers, leaving
item data uninitialized.
This makes tree-checker catch uninitialized data as error, causing
such panic.
*: These callers include but not limited to
setup_items_for_insert()
btrfs_split_item()
btrfs_expand_item()
[Fix]
Add a new parameter @check_item_data to btrfs_check_leaf().
With @check_item_data set to false, item data check will be skipped and
fallback to old btrfs_check_leaf() behavior.
So we can still get early warning if we screw up item pointers, and
avoid false panic.
Cc: Filipe Manana <fdmanana@gmail.com>
Reported-by: Lakshmipathi.G <lakshmipathi.g@gmail.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It's no doubt the comprehensive tree block checker will become larger,
so moving them into their own files is quite reasonable.
Signed-off-by: Qu Wenruo <quwenruo.btrfs@gmx.com>
[ wording adjustments ]
Signed-off-by: David Sterba <dsterba@suse.com>
